This invention relates to systems, methods and computer program products for identifying and/or verifying an individual, and more specifically to systems, methods and computer program products that use biometric data to identify and/or verify an individual.
Biometric information is now being used as an identification and/or verification technique for individuals. As is well known to those having skill in the art, biometric information is one or more behavioral and/or physiological characteristics of an individual. Biometric identification and/or verification uses a data processing system to enable automatic identification and/or verification of identity by computer assessment of a biometric characteristic. In biometric verification, biometric information is verified for a known individual. In biometric identification, biometric information for an individual is compared to known biometric information for many individuals in order to identify the individual.
Biometric identification/verification systems, methods and computer program products can measure one or more of the following behavioral and/or physiological characteristics of an individual: fingerprint, hand geometry, iris pattern, facial features, voice characteristics, handwriting dynamics, earlobe characteristics and keystroke dynamics. Other biometric characteristics may be used. Applications using biometric technologies include biometric check cashing machines, payment systems that substitute biometric data for personal identification numbers, access control systems that use biometric data, biometric employee time and attendance recording and biometric passenger control for transportation. Many other applications may utilize biometric information for identification and/or verification. See the publications entitled xe2x80x9cBiometrics, Is it a Viable Proposition for Identity Authentication and Access Controlxe2x80x9d, to Kim, Computers and Security, Vol. 14, 1995, pp. 205-214; xe2x80x9cA Robust Speaker Verification Biometricxe2x80x9d, to George et al., Proceedings, the IEEE 29th International Carnahan Conference on Security Technology, October 1995, pp. 41-46; xe2x80x9cOn Enabling Secure Applications Through Off-line Biometric Identificationxe2x80x9d, to Davida et al., Proceedings of the IEEE Computer Society Symposium on Research in Security and Privacy, 1998, pp. 148-157; and xe2x80x9cBiometric Encryption: Information Privacy in a Networked Worldxe2x80x9d, to Brown et al., EDI Forum: The Journal of Electronic Commerce, v. 10, No. 3, 1997, pp. 37-43.
FIG. 1 is a block diagram of conventional biometric identification and/or verification systems, methods and computer program products. In FIG. 1, biometric identification and/or verification is presented in a xe2x80x9cclient-serverxe2x80x9d environment using Internet plug-ins. As is well known to those having skill in the art, a server is a computer and/or a software program running on a computer and/or special purpose hardware that provides a specific kind of service to a client. A client is a computer and/or a software program running on a computer and/or special purpose hardware that is used to contact and obtain data from a server over a communications network. The client and server each may comprise one or more mainframe, midrange and/or personal computers and/or one or more applications running on one or more of these computers and/or special purpose hardware. The client and server may run on the same computer or on different computers. The communications network may be a local area network, a wide area network, the Internet, an application interface and any other communication mechanism that may be used to connect a client and a server. When using the Internet as a communication network between a client and a server, a web browser may be used as a client and a web server may be used as a server.
Referring now to FIG. 1, a client 10 communicates with a server 12 over the Internet 14. The client 10 includes a browser 16, and the server 12 includes a web server 18. When biometric identification and/or verification is used for electronic commerce between clients and servers over the Internet, a client biometric plug-in 22 and a server biometric script 24 may be used. For example, a biometric plug-in for a Netscape browser, such as Netscape Communicator or Netscape Navigator, may be used. At the server, a Uniform Resource Locator (URL) from the client invokes a script which can include and/or invoke one or more application programs to perform biometric functions. The design and use of plug-ins and scripts are well known to those having skill in the art and need not be described further herein.
Still referring to FIG. 1, the client biometric plug-in 22 includes biometric data acquisition 32 that performs sampling of a biometric characteristic at the client to generate samples related to the biometric characteristic. In order to provide secure transmission of the samples from the client 10 to the server 12, an encryption module 34 may use conventional encryption techniques such as the Data Encryption Standard (DES) algorithm to encrypt the samples. Added security may be obtained using a signature module 36, which may use an RSA public key algorithm or other conventional signature algorithm to add a signature to the encrypted samples. Accordingly, the client biometric plug-in transmits encrypted and signed samples, denoted ENC(SAMPLES), SIGNED in FIG. 1, from the client 10 to the server 12 over the Internet 14 using the browser 16 and the web server 18.
At the server 12, the server biometric script 24 includes and/or can invoke a signature verification module 46 that verifies the signature, for example using the RSA public key algorithm, and a decryption module 44 that decrypts the encrypted samples, for example using the DES algorithm. The samples are then applied to a template compare module 42 which contains therein a plurality of templates T1-Tn. Techniques for comparing templates to verify biometric data are well known to those having skill in the art and need not be described further herein.
Unfortunately, the use of encryption and/or signatures may be disadvantageous in biometric applications. For example, if the biometric data is 1.2K byte fingerprint data that is encrypted on a smart card, and is transmitted to a finger-scan reader for verification, the RSA signature may take more power and time, and may run the risk of signal corruption. DES encryption also may use complex key management techniques in order to establish a common secret encryption key at the client and at the server. Thus, the use of high security algorithms, such as DES and RSA algorithms may increase the cost and/or complexity of the overall biometric application. As the cost of biometric technology decreases, the cost of security may become a dominant factor in inhibiting the widespread use of biometric technology. Moreover, in some cases, the use of complex high-speed encryption, with its associated high cost, may even be unwarranted. Accordingly, it would be desirable to provide systems, methods and computer program products that can secure the biometric data during transmission, without unduly increasing the cost and/or complexity of the biometric application.
It is therefore an object of the present invention to provide improved biometric identification and/or verification systems, methods and computer program products.
It is another object of the present invention to provide biometric identification and/or verification systems, methods and computer program products that need not use encryption and/or signatures to transmit biometric data from a client to a server.
These and other objects are provided, according to the present invention, by performing key-dependent sampling of a biometric characteristic at the client, to thereby generate key-dependent biometric data samples. The key-dependent biometric data samples are then transmitted from the client to the server.
The present invention stems from a realization that in order to transmit biometric data from a client to a server, a biometric characteristic is generally sampled at the client. By sampling the biometric characteristic at the client in a key-dependent manner, the key-dependent biometric data samples may be transmitted from the client to the server without the need for additional encryption and/or a signature.
According to the invention, a key is preferably transmitted from the server to the client. The key is then used to perform the key-dependent sampling of the biometric characteristic at the client. The key-dependent sampling may be performed by sampling the biometric characteristic at a sampling frequency that is a function of the key. Alternatively, the key can be applied to the sampled biometric data, to thereby generate the key-dependent biometric data samples that are a function of the key. In a preferred embodiment, the key is used to perform nonlinear key-dependent sampling of the biometric characteristic at the client, for example by using the key to determine the sampling frequency and also using the key to apply a nonlinear function to the sampled biometric data. Nonlinear function may be a one-way function such as a hash function. Further encryption of the biometric data and/or the use of a signature with the biometric data need not be performed.
At the server, the key is also applied to at least one template, to thereby obtain key-dependent biometric data template samples. A comparison is then made between the key-dependent biometric data and the at least one key-dependent biometric data template samples at the server, in order to identify and/or verify the biometric characteristic.
The key may be transmitted from the server to the client in an unsecured manner (in the clear). A new key is preferably transmitted prior to each biometric characteristic sampling. Alternatively, if encryption is already present, the key may be encrypted. The key may include more than one value that is used to perform key-dependent sampling of biometric characteristics. For example, if the nonlinear sampling function is a cosine function, the frequency and phase of the cosine function may be transmitted as the key, to govern the sampling rate and the function that is applied to the sampled biometric data. Alternatively, if the client and the server both share a secret value, the key may be a random value that is transmitted from the server to the client in the clear. The random value may then be used in combination with the secret value, to perform key-dependent sampling.
Accordingly, biometric data may be securely transmitted from a client to a server without requiring complex encryption and/or signatures. Secure electronic commerce may thereby be provided in an efficient manner. It will be understood that the present invention may take the form of systems, methods and/or computer program products.